By means of the color development treatment following the exposure of a silver halide light-sensitive material to light, a reaction takes place between the aromatic primary amine developing agent, which has been oxidized by the silver halide, and a dye-forming coupler, and a color image is formed.
In this method, color reproduction by the subtractive method is commonly used, and to reproduce blue, green and red colors, yellow, magenta and cyan color images, which are in a complementary color relation, respectively, are formed.
Conventionally, phenols or naphthols are mainly used as the couplers for forming the cyan color image. However, a number of problems exist in terms of the stability of the color image obtained from conventional phenols and naphthols. For example, in U.S. Pat. Nos. 2,367,531, 2,369,929, 2,423,730 and 3,772,002, etc., there are disclosed color images obtained from 2-acylaminophenol cyan couplers, but these, in general, have poor fastness to heat. Also, color images obtained from 2,5-diacylaminophenol cyan couplers as described in U.S. Pat. Nos. 2,772,162 and 2,895,826, in general, have the disadvantage of poor light fastness. Further, color images obtained from the 2-ureidophenol cyan couplers as described in U.S. Pat. Nos. 3,446,622 and 4,333,999, in general, have poor light fastness, while the 1-hydroxy-2-naphthamido cyan couplers, in general, are inadequate both in terms of light and heat fastness (especially wet heat fastness).
A color image obtained from a phenolic coupler having a chain or branched alkyl group in the ballast group as described in JP-A-61-39045 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") has outstanding fastness to light and heat, but has the disadvantage that, following treatment, regions which were unexposed to light are nonetheless stained cyan.
Attempts to improve fastness in the case of the cyan coupler using an epoxy type coupler solvent have been described in U.S. Pat. Nos. 4,239,851 and 4,540,657, and in JP-A-62-75447, but while an improvement in fastness is noted with the combinations of epoxy compound and cyan coupler actually described in these specifications, the improvement cannot be said to be sufficient. Further, there is practically no effect with respect to the unacceptable cyan staining of the unexposed regions.